SOLUTION: Find an equation for the line parallel to 4y+8x=28 and goes through the point (−6,−3). Write your answer in the form y=mx+b.

Algebra ->  Equations -> SOLUTION: Find an equation for the line parallel to 4y+8x=28 and goes through the point (−6,−3). Write your answer in the form y=mx+b.       Log On


   

Question 1142060: Find an equation for the line parallel to
4y+8x=28
and goes through the point
(−6,−3).
Write your answer in the form
y=mx+b.
Found 2 solutions by josmiceli, ikleyn:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+4y+%2B+8x+=+28+
Divide both sides by +4+
+y+%2B+2x+=+7+
+y+=+-2x+%2B+7+
This is in the form +y+=+m%2Ax+%2B+b+
where +m+ = slope, so
+m+=+-2+
Any line parallel to this line will also
have slope = +m+=+-2+
So now I have:
+y+=+-2x+%2B+b+ where +b+ = y-intercept
----------------------------------------------------
The unknown line must go through point (-6,-3),
so I can say:
+-3+=+-2%2A%28-6%29+%2B+b+
+-3+=+12+%2B+b+
+b+=+-15+
+y+=+-2x+-+15+
------------------------------
check:
Does the line go through (-6,-3) ?
+-3+=+-2%2A%28-6%29+-+15+
+-3+=+12+-+15+
+-3+=+-3+
OK

Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
.
Any line parallel to the given line 


    4y + 8x = 28    (1)


has an equation


    4y + 8x = c     (2)


with the same left side as the given line (1) has  and some constant term "c" in the right side.


The constant term value "c" in (2) is determined from the condition that the point (-6,-3) lies on this line (2).


For it, substitute the coordinates  x= -6, y= -3 into equation (2) and determine "c".


    4*(-3) + 8*(-6) = c

    -12     - 48    = c

    -60             = c.


Thus you just determined  c = -60, and your equation is


    4y + 8x = -60.


You can simplify it by dividing both sides by 4


    y + 2x = - 15,


or, to get the requested form,


    y = -2x - 15.


It is your final answer.

Solved.